Use Photoshop to color black and white photos

In today’s life, many people’s homes have some old photographs of the past, but due to the objective conditions at the time, most of these photos were black and white. The people in the photographs are not absent from their youth. They are passing away. They want to relive or cherish the memory of their style. They always feel that they lack a true color and cannot but say it is a pity. There are many ways to color these pictures, but it's not easy to be able to make the color realistic. Here's a way to color black and white photos with Photoshop computer software. Personal feelings can be made more realistic and natural.

First, the basic principles and methods of coloring

The color of a person's skin naturally changes in the photo, and the color is complex and abundant. But in theory, we can assume that a person's skin hue and saturation are only related to human race, but for the same person, we can assume that the two parameters of all skin colors are basically fixed. However, the reason why the skin color on the portrait photos is rich and varied is the influence of external lighting, that is, brightness, and the colors in the same brightness area are basically the same. According to this hypothesis, we only need to color the skin color of the photos according to the brightness parameters. Finally, a natural transition process can be done.

Second, color examples

1. Scan the photo into your computer and convert it to Lab mode. Since the brightness will become a major identification parameter during the operation, the Lab mode can be used to operate the brightness channel (L channel) so that we can meet different color requirements depending on the brightness. Here is a picture of a child as an example.

2. Make a selection, use the selection tool to select all of the portrait's skin, use "Layer" → "New" → "Layerviacut". In this way, the skin of the person to be used can be individually layered, and the hair of the person can also be built separately in the same way.

3. Specify the current operation layer as the skin layer, turn to the channel panel, and select “Luminance Channel (L channel). In the toolbar, specify the foreground color as L:95, a:0, b:0. Execute the command in the menu. : "Select" → "Color Range", the tolerance parameter is set to be between 20 and 30, so that all the regions in the brightness range in the picture can be selected.

4. Call the menu command: "Select" → "Load Selection". In the dialog box that pops up, select the intersection set option (that is, the last item Intersect with selection, the same below) so that all selections are guaranteed to be within the skin.

5. In the channel control panel, specify the Lab synthesis channel (that is, the first channel). The foreground color is specified as: L:95 unchanged, a:5, b:19.

6. Select the brush tool in the toolbox. The coloring mode of the tool is set to Color. Set the brush brush to 60 or more (it can be larger, this can increase the speed of coloring). Note: The Color mode is a mode that maintains the brightness and draws and creates the resulting color using the hue and saturation of the specified foreground color.

7. Use the brush tool to paint in the selected area of ​​the image until all the constituencies have been painted.

8. Cancel the selection and start coloring the next brightness. Select the L channel in the channel panel, set the foreground color to LAB90, 0, 0, call the menu “Select” → “ColorRange”, and set the color tolerance value to 30. Make constituencies.

9. Call the menu item: "Select" → "Load Selection". Select the intersection option in the popup dialog box to select the skin of this brightness range.

10. Select the LAB synthesis channel in the channel panel and change the foreground color to L:90, a:9, b:27.

11. Use a brush tool to color the selection.

12. Start to color the next brightness, select the L channel in the channel panel, set the foreground color as: LAB80,0,0, call the menu "Select" → "ColorRange", set the color tolerance value to 30, press OK made a constituency.

13. Call the menu item: "Select" → "Load Selection". Select the intersection option in the popup dialog box to select the skin of this brightness range.

14. Select the LAB synthesis channel in the channel panel. Change the foreground color to L:90, a:15, and b:29.

15. Use brush tools to color the constituency.

16. Cancel the selection, start coloring the next brightness, select the L channel in the channel panel, set the foreground color to: LAB60, 0, 0, call the menu "Select" → "ColorRange", set the color tolerance value to 30. Press OK to make a selection.

17. Call the menu item: "Select" → "Load Selection". Select the intersection option in the popup dialog box to select the skin of this brightness range.

18. Select the LAB synthesis channel in the channel panel. Change the foreground color to L:60, a:22, and b:27.

19. Use brush tools to color the constituency.

20. Cancel the selection, start coloring the next brightness, select the L channel in the channel panel, set the foreground color as: LAB50, 0, 0, call the menu "Select" → "ColorRange", and set the color tolerance value as 50. Press OK to make the selection.

21. Call the menu item: "Select" → "Load Selection". Select the intersection option in the popup dialog box to select the skin of this brightness range.

22. Select the LAB synthesis channel in the channel panel. Change the foreground color to L:50, a:22, and b:23.

23. Use brush tools to color the constituency.

24. Start coloring the next brightness. Select the L channel in the channel panel, set the foreground color to: LAB35,0,0, call the menu “Select” → “Color Range”, and set the color tolerance value to 50. Press OK to make the selection.

25. Call the menu item: "Select" → "Load Selection", in the pop-up dialog box, select the intersection set option to select the skin of this brightness range.

26. Select the LAB synthesis channel in the channel panel. Change the foreground color to L:35, a; 23, and b:28.

27. Use brush tools to color the constituency.

28. Cancel the selection, start coloring the next brightness, select the L channel in the channel panel, set the foreground color as: LAB20,0,0, call the menu "Select" → "ColorRange", set the color tolerance value to 50. Press OK to make the selection.

29. Call the menu item: "Select" → "Load Selection", select the intersection option in the pop-up dialog box, select the skin of this brightness range.

30. Select the LAB synthesis channel in the channel panel. Change the foreground color to L:20, a:21, and b:26.

31. Use a brush tool to color the constituency.

32. At this point, the first job of painting has basically been completed and the constituency has been cancelled. However, the problem is that the color transition between different brightnesses is very hard and the next step is to perform natural transition processing.

33. In the channel control panel, select a channel, call the menu command: "Filter" → "Blur" → "GaussianBlur", adjust the parameter Radius value, to see if there is traces of the skin is good (usually in 12 ~ 16 )between.

Do the same for the b channel. In the channel panel, select: LAB synthesis channel viewing effect. The same method can be used for other parts of the image: hair, clothing, lips, etc., and will not be described in detail here.

For those who have no coloring experience, how to determine the color of a certain brightness is a difficult task. At the beginning, you can open a color photo of a person with similar characteristics (almost age person), and turn to Lab mode. Use the mouse to detect the corresponding reference value in the picture. The value can be seen in the Info control panel.